WO2020109573A1

WO2020109573A1 - Interconnector for reactor for electrolysis or co-electrolysis of water (soec) or fuel cell (soefc), associated manufacturing process

Info

Publication number: WO2020109573A1
Application number: PCT/EP2019/083130
Authority: WO
Inventors: Michel Planque; Charlotte Bernard; Guilhem Roux
Original assignee: Commissariat A L'energie Atomique Et Aux Energies Alternatives
Priority date: 2018-11-29
Filing date: 2019-11-29
Publication date: 2020-06-04
Also published as: FR3089357B1; EP3888168A1; FR3089357A1

Abstract

The invention relates to a device forming an electrical and fluidic interconnector for the high-temperature electrolysis or co-electrolysis of steam or for a fuel cell (SOFC). According to the invention, the device consists of a single one-piece part made of metal alloy, extending along two axes of symmetry (X, Y) that are orthogonal to one another, which part is pierced with ports with passages allowing fluidic communication between certain ports, which passages are formed by porous regions and/or tongues forming combs inside the frame. The invention also relates to the process for manufacturing such an interconnector according to which the part is made in a single step by additive manufacturing.

Description

Title: Interconnector for water electrolysis or co-electrolysis reactor (SOEC) or fuel cell (SOEFC), Associated manufacturing process.

Technical area

The present invention relates to the field of solid oxide stacks (SOEC / SOFC), for the production of solid oxide fuel cells (SOFC, acronym for "Solid Oxide Fuel Cell"), but also for the production of reactors electrolysis of water at high temperature (EHT, or EVHT for electrolysis of water vapor at high temperature to produce hydrogen d'eau from water vapor H2O, or HTE acronym for High Temperature Electrolysis, or also HTSE English acronym for High Temperature Steam Electrolysis) also with solid oxides (SOEC, English acronym for “Solid Oxide Electrolyser Cell”), and for high temperature co-electrolysis of water and another gas chosen from dioxide carbon dioxide or nitrogen dioxide NO2.

The invention relates more particularly to a new embodiment of the electrical and fluidic interconnectors for the distribution of electrical current and gases within a high temperature water electrolysis or co-electrolysis reactor (EHT) of SOEC type, or a SOFC type fuel cell.

Although described with reference mainly to the application of electrolysis of water at high temperature, the invention applies equally well to a co-electrolysis of water and another gas chosen from carbon dioxide CO2 or NO2 nitrogen dioxide, than to a SOFC fuel cell.

The invention applies to a SOFC fuel cell using as fuel either hydrogen or hydrocarbon, for example methane CH4.

Prior art

The electrolysis of water an electrolytic reaction which breaks down water into dioxygen and dihydrogen gas with the help of an electric current according to the reaction:

H ₂ 0 H ₂ + ½ 0 ₂

To carry out the electrolysis of water, it is advantageous to carry it out at high temperature, typically between 600 and 950 ° C., since part of the energy necessary for the reaction can be provided by heat which is less expensive than electricity and activation of the reaction is more efficient at high temperatures and does not require a catalyst. To implement electrolysis at high temperature, it is known to use an electrolyser of the SOEC type (English acronym for "Solid Oxide Electrolyser Cell"), consisting of a stack of elementary patterns each comprising a solid oxide electrolysis cell, consisting three anode / electrolyte / cathode layers superposed one on the other, and interconnection plates of metal alloys also called bipolar plates, or interconnects. The interconnects have the function of ensuring both the passage of electric current and the circulation of gases in the vicinity of each cell (water vapor injected, hydrogen and oxygen extracted in an EHT electrolyser; air and hydrogen injected and water extracted in an SOFC cell) and to separate the anode and cathode compartments which are the gas circulation compartments on the side of the anodes and cathodes respectively of the cells. To carry out the electrolysis of water vapor at high temperature EHT, water vapor H2O is injected into the cathode compartment. Under the effect of the current applied to the cell, the dissociation of water molecules in vapor form is carried out at the interface between the hydrogen electrode (cathode) and the electrolyte: this dissociation produces dihydrogen gas ¾ and oxygen ions. Dihydrogen is collected and discharged at the outlet of the hydrogen compartment. The oxygen O ² ions migrate through the electrolyte and recombine into oxygen at the interface between the electrolyte and the oxygen electrode (anode). As shown diagrammatically in FIG. 1, each elementary electrolysis cell 1 is formed by a cathode 2 and an anode 4, placed on either side of a solid electrolyte 3 generally in the form of a membrane. The two electrodes (cathode and anode) 2,4 are electrical conductors, made of porous material, and the electrolyte 3 is gas tight, electronic insulator and ionic conductor. The electrolyte can in particular be an anionic conductor, more precisely an anionic conductor of the O ² and G ions, the electrolyser is then called an anionic electrolyser.

The electrochemical reactions take place at the interface between each of the electronic conductors and the ionic conductor.

At cathode 2, the half-reaction is as follows:

2 H2O + 4 e ® 2 ¾ + 2 O ² .

At anode 4, the half-reaction is as follows:

20 ² ® 0 ₂ + 4 e.

The electrolyte 3 interposed between the two electrodes 2, 4 is the place of migration of the O ² ′ ions under the effect of the electric field created by the potential difference imposed between the anode 4 and cathode 2.

As illustrated in parentheses in FIG. 1, the water vapor entering the cathode can be accompanied by hydrogen ¾ and the hydrogen produced and recovered at the outlet can be accompanied by water vapor. Similarly, as illustrated in dotted lines, a draining gas, such as air can also be injected at the inlet to evacuate the oxygen produced. The injection of a draining gas has the additional function of playing the role of thermal regulator.

An elementary electrolysis reactor consists of an elementary cell as described above, with a cathode 2, an electrolyte 3, and an anode 4 and two monopolar connectors which provide the electrical, hydraulic and thermal distribution functions. To increase the flow rates of hydrogen and oxygen produced, it is known to stack several elementary electrolysis cells one on top of the other, separating them by interconnection devices, usually called interconnectors or bipolar interconnection plates. The assembly is positioned between two end interconnection plates which support the electrical supplies and gas supplies of the electrolyser (electrolysis reactor).

A high temperature water electrolyser (EHT) thus comprises at least one, generally a plurality of electrolysis cells stacked on each other, each elementary cell being formed of an electrolyte, a cathode and an anode, the electrolyte being interposed between the anode and the cathode.

The fluidic and electrical interconnection devices which are in electrical contact with one or more electrodes generally perform the functions of supplying and collecting electric current and delimit one or more compartments for the circulation of gases.

Thus, a so-called cathode compartment has the function of distributing electric current and water vapor as well as recovering hydrogen from the cathode in contact.

A so-called anode compartment has the function of distributing the electric current as well as recovering the oxygen produced at the anode in contact, possibly using a draining gas.

FIG. 2 represents an exploded view of elementary patterns of a high temperature water vapor electrolyser according to the state of the art. This EHT electrolyser comprises a plurality of elementary electrolysis cells Cl, C2 ... of solid oxide type (SOEC) stacked alternately with interconnectors 5. Each cell Cl, C2 ... consists of a cathode 2.1, 2.2 , ... and an anode 4.1, 4.2, between which an electrolyte 3.1 is placed, 3.2 .... All the electrolysis cells are supplied in series by the electric current and in parallel by the gases.

The interconnector 5 is a metallic alloy component, electronic conductor, which ensures the separation between the cathode 50 and anode 51 compartments, defined by the volumes between G interconnector 5 and the adjacent cathode 2.1 and between G interconnector 5 and the anode adjacent 4.2 respectively. It also ensures the distribution of gases to the cells. The injection of water vapor into each elementary pattern is done in the cathode compartment 50. The collection of the hydrogen produced and of the residual water vapor at the cathode 2.1, 2.2 ... is carried out in the cathode compartment 50 downstream of cell C1, C2 ... after dissociation of the water vapor by the latter. The oxygen produced at anode 4.2 is collected in the anode compartment 51 downstream of the cell C1, C2 ... after dissociation of the water vapor into oxygen ions by the latter.

The interconnector 5 ensures the passage of current between the cells C1 and C2 by direct contact with the adjacent electrodes, that is to say between the anode 4.2 and the cathode 2.1.

In a SOFC solid oxide fuel cell according to the state of the art, the cells Cl, C2 ... and interconnectors 5 used are the same components, but the operation is opposite to that of an EHT electrolyser as it comes to be explained with a reverse current direction, with air which supplies the cathode compartments and hydrogen as fuel which supplies the anode compartments.

Satisfactory operation of an EHT electrolyser requires among others the following essential functions:

A / good electrical insulation between two adjacent interconnectors in the stack, under penalty of short-circuiting the elementary electrolysis cell interposed between the two interconnectors;

B / a good seal between the two separate compartments, i.e. anodic and cathodic, under penalty of recombination of the gases produced resulting in a reduction in yield and above all the appearance of hot spots damaging the electrolyser; this corresponds to finding a complete initial voltage (English acronym "OCV" for Open Cell Voltage);

C / a good distribution of the gases both at the inlet and at the recovery of the gases produced, under penalty of loss of yield, inhomogeneity of pressure and temperature within the various elementary cells or even prohibitive degradations of the cells; that corresponds to finding the lowest polarization resistance;

D / a good electrical contact and a sufficient contact surface between each cell and interconnector, in order to obtain the lowest ohmic resistance between cells and interconnectors.

As regards the geometry of the interconnectors, a channel plate is usually used as an interconnector both in EHT electrolysers and in SOFC fuel cells. The channel plates were first made of a nickel-chromium alloy, such as Haynes® 230®, then of a chromium-iron alloy, in particular of Crofer® 22 APU.

One of the major drawbacks of this channel plate is linked to its production technique. Thus, these plate structures require a large thickness of material, typically 5 to 10 mm, for the area of collection of the gases produced and shaping by mass machining, of the gas distribution channels. The material and machining costs are significant and directly related to the fineness of pitch of the channels to be machined, more particularly distances between channels less than 1 mm.

Another major drawback is that, as already mentioned, it is necessary to have channel depths in the plates which are relatively large, typically from 5 to 10 mm, in order to ensure a uniform distribution of the gases over all of the channels. from their cross feed. This relatively large depth of the channels implies a relatively large thickness of interconnecting plate and therefore a unit thickness of a relatively high elementary SRU pattern. In the end, the architectures with these channel interconnecting plates imply a relatively large height of an EHT reactor or of a SOFC fuel cell, which is therefore much greater than the heights of the electrochemical cells.

The use of thin sheets, typically 0.5 to 2 mm, stamped and then assembled together by laser welding has already been tested. This technique has the advantage of limiting the cost of raw material but does not make it possible to achieve a fineness of channels as high as by machining. In fact, the possibilities of realization for the depth of the channels, the unit width of tooth and the pitch between teeth are limited. In addition, the cost of stamping tools requires mass production.

The Applicant has produced an interconnector with three thin laminated sheets assembled together by welding. Such an interconnector 6 is illustrated in FIGS. 3 and 4: it consists of three flat sheets 7, 8, 9 elongated along two axes of symmetry (X, Y) orthogonal to each other, the flat sheets being laminated and assembled together by welding laser by transparency.

Thus, a central sheet 8 is interposed between a first 7 and a second end sheet 9.

The first 7 end plate is intended to come into mechanical contact with the plane of a cathode 2.1 of a cell (C1) of elementary electrolysis and the central plate 8 is intended to come into mechanical contact with the plane of an anode 4.2 of an adjacent elementary electrolysis cell (C2).

One of the end sheets 7 called the first end sheet, and the central sheet 8 each have an undrilled central part 75, 85.

This first end plate 7 is pierced at the periphery of its central part 75, with four slots 71 to 74. The first 71 and second 72 slots are elongated over a length corresponding to part of the length of the central portion along the 'one of the X axes, while the third 73 and fourth 74 lights are elongated over a length corresponding substantially to the length of the central part along the other of the Y axes.

The same goes for the central sheet 8: it is pierced at the periphery of its central part 85, with four slots 81 to 84. The first 81 and second 82 slots are elongated over a length corresponding to part of the length of the central part along one of the X axes, while the third 83 and fourth 84 slots are elongated over a length corresponding substantially to the length of the central part along the other of the Y axes.

The first end plate 7, further comprises a fifth 76 and sixth 77 lights arranged symmetrically on either side of the axis X, inside its first to fourth lights, and are elongated over a corresponding length substantially to the length of the central part along the X axis.

The second end plate 9 has, at the periphery of its central part, four slots 91 to 94. The first 91 and second 92 slots are elongated over a length corresponding to part of the length of the central portion along the one of the X axes, while the third 93 and fourth 94 lights are elongated over a length corresponding substantially to the length of the central part along the other of the Y axes. The central part of the second end plate 9 is furthermore pierced by a fifth light 95. The second end plate 9 further comprises a sixth 96 and seventh 97 lights arranged symmetrically on either side of the Y axis, inside its first to fourth lights 91 to 94. These sixth 96 and seventh 97 lights are elongated over a length corresponding substantially to the length of the central part 95 along the other of the axes Y.

The first to fourth slots 81 to 84 of the central sheet 8 are widened relative to the first to fourth slots 71 to 74, 91 to 94 of each end sheet 7, 9 respectively.

All the enlarged openings 81 to 84 of the central sheet have in their enlarged part sheet metal tabs 810, 820, 830, 840 spaced apart from each other by forming a comb defining slots.

To make an interconnector 6, the three sheets 7, 8, 9 are laminated and assembled by welding together.

The sheet metal tabs 810, 820, 830, 840 then form spacers between the first 7 and the second 9 end sheets.

Each of the first to fourth lights of one of the three sheets is in fluid communication individually respectively with one of the first to fourth corresponding lights of the other two sheets.

The first lumen 71 of the first end plate 7 is in fluid communication with the fifth lumen 76 of the first end plate 7 through the slots of the first enlarged lumen 81 of the central plate 8.

The second light 72 of the first end sheet 7 is in fluid communication with the sixth light 77 of the first end sheet 7 through the slots of the second enlarged light 82 of the central sheet 8.

The third lumen 93 of the second end plate 9 is in fluid communication with the fifth lumen 95 of the second end plate 9 through the slots of the enlarged third lumen 83 of the central plate 8 and through the sixth lumen 96 of the second end plate 9.

The fourth lumen 94 of the second end plate 9 is in fluid communication with the fifth lumen 95 of the second end plate through the slots of the enlarged fourth lumen 84 of the central plate 8 and through the seventh light 97 of the second end plate 9. FIGS. 5 and 5A show in detail the embodiment of the comb formed by the sheet metal tongues 810 at the level of the enlarged slot 81 of the central sheet and its arrangement between the two end sheets 7, 9, in order to allow the supply an electrolysis cell, here in H2O water vapor. Thus, the comb formed 810, 811 allows the water vapor to pass from the supply clarinet 71, 81, 91 to the distribution slot 76 while passing in the space between the two end sheets 7, 9 The thickness of the central sheet 8 at this comb 810, 811 gives it a spacer function and thus guarantees the height of the passage for water vapor in the inter-sheet end space 7, 9 .

To make a stack of electrolysis reactors or fuel cells, there are also made through holes 78, 88, 98; 79, 89, 99 through the three sheets 7, 8, 9. Thus, these through holes make it possible to guide all of the components of the same stack by tie rods or columns positioned within a single circular hole 78, 88, 98 with a centering function within each component and a single oblong hole 79, 88, 98 with a positioning function to ensure correct positioning by controlling the free movements and the blocked movements.

Such an interconnector 6 with three thin sheets assembled 7, 8, 9 is very advantageous. Thus, the passage of gases through the interior of G interconnector 6 has the advantage of freeing up a flat surface for the production of seals. In addition, thanks to the comb shapes for the widened slots 81, 85, a uniform distribution of each gas (H2O, CO2, Air) is obtained over the electrolysis cell, and thanks to these comb shapes for the widened slots 83, 86 recovery of the gas produced (¾, CO, O2).

However, the production of an interconnector 6 with three assembled thin sheets is not satisfactory for the following reasons.

First of all, the production of thin sheets on conventional conventional machines involves a lot of machining. We must first start with a strip of sheet metal from which we will pre-cut the required formats. Then, the sheets pass through a laser cutting unit, in order to obtain the desired geometry. They are then assembled by a laser welding process by transparency, according to a particular diagram of continuous lines, which aims to isolate the gas circuits to force it to follow a determined path, as explained above. This transparency laser welding operation turns out to be the most delicate, and also the most expensive. To finalize the realization, the assembly of the sheets passes over a bench, known as stress relieving, in order to flatten the assembly which may have been deformed at the end of the laser welding operation by transparency.

Each interconnector obtained must be checked for leaks, and in the event of a leak, a step to resume the welding concerned is necessary.

All of these operations for producing an assembled thin sheet interconnector represent a very significant cost, as well as multiple manipulations.

There is therefore a need to improve the production of interconnectors dedicated to electrolysers (EHT) or co-electrolysers of SOEC type or to fuel cells of SOFC type, in particular in order to reduce their production cost and limit their handling during production. .

An object of the invention is to meet this need at least in part.

Statement of the invention

To do this, the invention relates in one aspect, an electrical and fluidic interconnector for the electrolysis or co-electrolysis at high temperature of water vapor or for a fuel cell (SOFC).

According to the invention, the device consists of a single monobloc piece of metal alloy, elongated along two axes of symmetry (X, Y) orthogonal to each other, the piece comprising: a solid central part, one of the faces of which is formed by one cavity is intended to come into mechanical contact with the plane of a cathode of an elementary electrochemical cell and the other of the faces is intended to come into mechanical contact with the plane of an anode of an adjacent elementary electrochemical cell , each of the two adjacent elementary cells of SOEC type being formed by a cathode, an anode, and an electrolyte interposed between the cathode and the anode,

a peripheral part forming a frame around the central part, the frame being provided with four lights, the first and second of the four lights being elongated over a length corresponding to part of the length of the central part along one of the axes X being distributed on either side of said X axis, while the third and fourth of the four lights are elongated over a length corresponding substantially to the length of the central part along the other of the Y axes while being distributed on both sides and on the other of said axis Y. According to the invention, on the one hand the first and the second lumen are in fluid communication with one of the faces of the central part, on the other hand the third and the fourth light are in fluid communication with the other of the faces of the central part, the passages ensuring the fluid communications being produced by porous zones and / or tongues forming combs inside the frame.

In another aspect, the invention relates to a method for manufacturing an electrical and fluidic interconnector described above, according to which the part is produced in a single step by additive manufacturing.

The single monobloc piece of an interconnector is preferably made of ferritic steel with about 20% chromium, preferably made of CROFER® 22APU or stainless steel of grade K41X.

During a single step by additive manufacturing, it is possible to manufacture a very large number of one-piece interconnectors, which makes it possible to mobilize a single machine. Thus, the invention makes it possible to manufacture interconnectors dedicated to the electrolysis / co-electrolysis of water at high temperature or to fuel cells (SOFC) in large series by reducing the cost and the time of the manufacturing steps. 'interconnects according to the state of the art, in particular welding of the plates by laser.

Preferably, the single piece is made of ferritic stainless steel, more preferably of grade K41X.

According to an advantageous characteristic, the thickness of the part is at least equal to 400 microns.

According to an advantageous embodiment, the porous zones have a lattice structure. According to an advantageous variant, G interconnector comprises one or more through holes for positioning with centering G interconnector within a stack.

The invention also relates in another of its aspects to a method for manufacturing an electrical and fluidic interconnector described above, according to which the part is produced in a single step by additive manufacturing.

Advantageously, the direction of additive manufacturing is inclined at least 45 ° relative to one of the axes of G interconnector.

Preferably, the additive manufacturing is carried out by a selective laser fusion technique on a metal powder bed (FLLP). According to an advantageous embodiment, a single block is produced during the single step by additive manufacturing, comprising a plurality of parts, each forming an interconnector, then the individual cutting of each part is carried out.

According to an advantageous alternative embodiment, a stripping step is carried out, preferably by sandblasting or shot blasting, of each cut piece.

Other advantages and characteristics of the invention will emerge more clearly on reading the detailed description of examples of implementation of the invention made by way of illustration and not limitation, with reference to the following figures among which:

Brief description of the drawings

[Fig 1] Figure 1 is a schematic view showing the principle of operation of a high temperature water electrolyser.

[Fig 2] Figure 2 is a schematic exploded view of a portion of a high temperature water vapor electrolyser (EHT) of the SOEC type comprising interconnectors according to the state of the art.

[Fig 3] Figure 3 is a perspective view of an electrical and fluidic interconnector according to the state of the art, with three thin sheets (laminates) and assembled by welding, implemented in an EHT electrolyser or a battery fuel type SOFC.

[Fig 4] Figure 4 is an exploded top view of the interconnector according to the state of the art of Figure 3.

[Fig 4A] Figure 4A is a detail view of Figure 4.

[Fig 4B] FIG. 4B is a detailed perspective view of FIG. 4.

[Fig 5] Figure 5 is a schematic view illustrating additive manufacturing in one step of an electrical and fluidic interconnector according to the invention.

[Fig 6] Figure 6 is a partial schematic perspective view of an interconnector according to the invention.

[Fig 6 A] Figure 6 A is a detail view of Figure 6.

[Fig 7] Figure 7 is a partial schematic perspective view showing the detail of an interconnector according to a variant of the invention.

detailed description

Fes Figures 1 to 4B relating to the state of the art have already been commented on in the preamble. They are therefore not detailed below. To reduce the manufacturing costs and the handling times of an interconnector 6 with three thin sheets, laminated and assembled according to the state of the art, as described in the preamble, the inventors have thought of making such an interconnector with the same gas distribution functions, using additive manufacturing.

More specifically, the inventors believe that additive manufacturing by selective laser fusion of metallic powder (FLLP or SLM in English for “Selective Laser Melting”), as described in references [1] and [2], is particularly suitable. Thus, from a bed of metallic powder, preferably steel of grade K41X, a large number of interconnectors 10 can be produced, each consisting of a single monobloc piece, as shown in FIG. 5.

To carry out this manufacture of monoblock parts, care must be taken to comply with the additive manufacturing rules. In the context of selective laser powder fusion, parts with angles less than an angle a of the order of 45 ° should not be constructed.

Indeed, with this selective laser powder fusion technique, the maximum distance for the unsupported parts is around 2mm.

In the following example, making a letter A represents a part with a horizontal crossbar. Unless this bar is less than 2 mm long, vertical supports must be provided to prevent it from deforming.

Although not problematic in itself, this operation will generate rectification or machining costs for the removal of these supports after manufacture.

The same goes for the letter T which, without supports under its horizontal wings, these will collapse. The letters B, D, P and R are particularly problematic since the supports remain inside the part, that is to say where they are the most difficult to remove. This is also the case for rounded shapes like GO and Q, except to be very small. In fact, only the X and G Y require no form of support, but to do this, their arms will need to form an angle of at least 45 degrees with the horizontal.

Thus, an inclination at 45 ° between a main axis Y of G interconnector and the direction of additive manufacturing is appropriate, as symbolized in FIG. 5. Depending on the method of additive manufacturing, it may be necessary to increase the total thickness E of G interconnector 10 compared to an interconnector 6 with three thin sheets according to the state of the art. For example, for manufacturing in FLLP, one can choose a minimum wall thickness E equal to 400 μm. The one-piece interconnector 10 thus constituted comprises a central part 100 whose face formed by a cavity is intended to come into mechanical contact with the plane of a cathode 2 of an elementary electrochemical cell C2 and the other of the faces is intended to come into mechanical contact with the plane of an anode 4 of an adjacent elementary electrochemical cell (C1).

A peripheral part forming a frame around the central part is pierced with four main lights 101, 102, 103, 104.

The first light 101 is in fluid communication with the second light 102 passing through the cavity of the central part. In the context of the electrolysis of water, this fluid communication can be dedicated to the supply of air, as a draining gas, and recovery of the oxygen produced.

The third light 103 is in fluid communication with the fourth light 104 passing through the flat face of the central part, opposite the cavity. In the context of the electrolysis of water, this fluid communication can be dedicated to the supply of water vapor, and recovery of the hydrogen produced.

The passages ensuring fluid communications inside the frame are produced by tongues forming combs 106 (FIGS. 6 and 6A) and / or porous zones 106 ’(FIG. 7) inside the frame.

When one chooses to make combs 106, their thickness el is equal to at least 200pm, or a minimum total thickness E of G interconnector 100 to 400pm or even 500pm. In place of the combs 106, porous zones 106 ’can be produced which can be constructed in additive manufacturing by local modification of the printing parameters. These porous zones 106 ′ can advantageously have a lattice structure.

The realization of porous zones 106 'makes it possible to improve the distribution of gases within each electrolysis cell in contact with an interconnector 10 according to the invention because the gas which comes into contact with the central part 100, on one or the other of its faces, is distributed more homogeneously.

On the other hand, these porous zones 106 ′ can increase the pressure drops within an interconnector 10 according to the invention, and therefore consequently an increase in the pressure of the gas (water vapor, draining gas in the case of l 'electrolysis of water), upstream of the stack constituting the electrolysis reactor or a SOFC fuel cell. The additional advantage of an area 106 'in lattice structure is to reduce these pressure drops.

The production by additive manufacturing of G interconnector according to the invention 10 also makes it possible during the same step to make a circular hole 109 whose function is the centering of G interconnector during the production of a SOEC / SOFC stack and of an oblong hole 108 with positioning function to ensure correct positioning while controlling the free movements and the blocked movements.

Once the additive manufacturing has been carried out, the individual cut-outs of the interconnectors are made and then a surface treatment can be carried out, preferably by sandblasting or by shot blasting.

In addition, the centering and positioning holes 108, 109 can be taken up by mechanical machining to perfect their bore.

Other variants and advantages of the invention can be achieved without departing from the scope of the invention.

For example, provision may be made to make other holes / lights by additive manufacturing in an interconnector according to the invention, which can be used for example to pass instrumentation means, such as a thermocouple, or tension wires .

Although described for electrolysis of water at high temperature, the G interconnector according to the invention can equally well be used for co-electrolysis of water vapor mixed with either carbon dioxide or nitrogen dioxide.

Although described for electrolysis of water at high temperature, the G interconnector according to the invention can equally well be used as a SOFC fuel cell. In this case, the light 101 is supplied with fuel, for example hydrogen or methane, and the light 103 is supplied with air or oxygen.

The invention is not limited to the examples which have just been described; in particular, it is possible to combine characteristics of the examples illustrated within variants which are not illustrated.

List of documents cited

[1]: Sébastien PILLOT, Engineering Techniques "Selective laser fusion of a bed of metallic powders", Ref: BM7900 vl, February 10, 2016;

[2]: Laverne et al. - 2016, Engineering Techniques "Additive Manufacturing-General Principles", Ref: BM7017 V2, February 10, 2016

Claims

1. Electrical and fluidic interconnector (10) for the high temperature electrolysis or co-electrolysis of water vapor or for a fuel cell (SOFC), the device consisting of a single monobloc piece (10) of alloy metallic, elongated along two axes of symmetry (X, Y) orthogonal to each other, the part comprising:

- A solid central part (100), one of the faces of which is formed by a cavity is intended to come into mechanical contact with the plane of a cathode (2) of an elementary electrochemical cell (C2) and the other of the faces is intended to come into mechanical contact with the plane of an anode (4) of an adjacent elementary electrochemical cell (C1), each of the two adjacent elementary cells of SOEC type being formed by a cathode (2), an anode (4), and an electrolyte (3) interposed between the cathode and the anode,

- a peripheral part forming a frame around the central part, the frame being provided with four lights (101, 102, 103, 104), the first and second of the four lights being elongated over a length corresponding to part of the length of the central part along one of the X axes being distributed on either side of said X axis, while the third and fourth of the four slots are elongated over a length corresponding substantially to the length of the central part along l 'other of the Y axes being distributed on either side of said Y axis;

in which on the one hand the first and the second lights are in fluid communication with one of the faces of the central part, on the other hand the third and the fourth lights are in fluid communication with the other of the faces of the part central, the passages ensuring the fluidic communications being produced by porous zones and / or tongues forming combs inside the frame.

2. Electrical and fluidic interconnector according to claim 1, the single part being made of ferritic stainless steel, preferably of grade K41X.

3. Electrical and fluidic interconnector according to claim 1 or 2, the thickness of the part being at least equal to 400 microns.

4. Electrical and fluidic interconnector according to one of the preceding claims, the porous zones having a lattice structure.

5. Electrical and fluidic interconnector according to one of the preceding claims, comprising one or more through holes (109) for positioning with centering G interconnector within a stack.

6. Method of manufacturing an electrical and fluidic interconnector according to one of the preceding claims, according to which the part is produced in a single step by additive manufacturing.

7. The manufacturing method according to claim 6, the direction of additive manufacturing being inclined at least 45 ° relative to one of the axes of G interconnector.

8. The manufacturing method according to claim 6 or 7, the additive manufacturing being carried out by a selective laser fusion technique on a bed of metallic powder (FLLP).

9. Manufacturing method according to one of claims 6 to 8, according to which is carried out during the single step by additive manufacturing, a single block comprising a plurality of parts each forming an interconnector, then we proceed to the individual cutting of each part.

10. The manufacturing method according to claim 9, according to which a stripping step is carried out, preferably by sandblasting or shot blasting, of each cut piece.